Photocatalytic Degradation Reaction Research Articles

Highly efficient TiO2 nanotubes for photocatalytic degradation reactions through optimization of textural properties

Highly efficient TiO2 nanotubes for photocatalytic degradation reactions through optimization of textural properties

Facile fabrication of MoS2 and MoSe2 layered structures on Mo foil for the efficient photocatalytic dye degradation and electrocatalytic hydrogen evolution reaction

The rapidly growing necessity for sustainable materials in fields such as energy, environmental science, and medicine, two dimensional-based photo- and electro-catalysts has obtained mounting consideration. A simple methodology was employed to fabricate MoSe2 and MoS2 layered structures on flexible Mo foil as heterogeneous catalysts for the electrocatalytic hydrogen evolution reaction (HER) and the photocatalytic decolorization of chromic red (CR) and methylene blue (MB) dyes. The structural characteristics confirm the formation of the multi-layer thick MoSe2 and MoS2 nanofilms. The toxic MB and CR dyes were rapidly and effectively decolorized in polluted water by the photocatalysts within 30 min of UV-light irradiation. The fabricated layered structures exhibited favorable HER electrocatalytic activities along with low overpotentials, small Tafel slopes, and excellent 24-h stability performances. The strong catalytic behavior of these structures fabricated on Mo foil in relation to the HER reaction and the dye decolorization process make them suitable candidates for the catalyst industry.

Photocatalytic degradation of 4‐nitrophenol by using multicomponent Cu2O‐Cu@TiO2 nanoparticle aggregates

AbstractMulticomponent nanomaterials with synergistic effect were typically used to enhance the photocatalytic performance. Herein, three‐component nanomaterials composed of Cu2O, Cu, and TiO2 were prepared using a facile method, and applied in the photocatalytic degradation reactions. The synthetic procedure involves the formation of Cu2O nanoparticle aggregates (NPAs) followed by Cu nanoparticles growth on the surface of Cu2O NPAs in one pot, and TiO2 encapsulation (Cu2O‐Cu@TiO2). The catalyst structure was characterized by x‐ray diffraction, field emission‐scanning electron microscopy, transmission electron microscopy, and energy‐dispersed x‐ray. The catalytic performance of Cu2O‐Cu@TiO2 NPAs was evaluated through the photocatalytic degradation of 4‐nitrophenol under the simulated solar light. We found that it exhibited greater activity than the Cu2O‐Cu NPAs, commercial TiO2, and Cu2O@TiO2 NPAs, probably due to their synergistic interactions resulting in the effective photogenerated carrier transfer in the multicomponent nanomaterials.

In Situ Multicolor Imaging of Photocatalytic Degradation Process of Permanganate on Single Bismuth-Based Metal-Organic Frameworks.

Bismuth-based metal-organic frameworks (Bi-MOFs) have emerged as important photocatalysts for pollutant degradation applications. Understanding the photocatalytic degradation mechanism is key to achieving technological advantage. Herein, we apply dark-field optical microscopy (DFM) to realize in situ multicolor imaging of the photocatalytic degradation process of permanganate (MnO4-) on single CAU-17 Bi-MOFs. Three reaction kinetic processes such as surface adsorption, photocatalytic reduction, and disproportionation are revealed by combining the time-lapsed DFM images with optical absorption spectra, indicating that the photocatalytic reduction of purple MnO4- first produces beige red MnO42- through a one-electron pathway, and then MnO42- disproportionates into yellow MnO2 on CAU-17. Meanwhile, we observe that the deposition of MnO2 cocatalysts enhances the surface adsorption reaction and the photocatalytic reduction of MnO4- to MnO42-. Unexpectedly, it is found that isopropanol as a typical hole scavenger can stabilize MnO42-, avoiding disproportionation and causing the alteration of the photocatalytic reaction pathway from a one-electron avenue to a three-electron (1 + 2) process for producing MnO2 on CAU-17. This research opens up the possibility of comprehensively tracking and understanding the photocatalytic degradation reaction at the single MOF particle level.

Effect of adding silver on photocatalytic properties of ZnAl2O4 nanopowder synthesized using microemulsion and polyacrylamide gel methods for recycled water

In recent decades, water purification and removal of organic pollutants such as organic dyes have been among the most important issues. Photocatalyst is one of the most effective methods for recycled water to eliminate organic pollutants and break them down into safe compounds. One of the most significant factors for determining the efficiency of photocatalyst nanoparticles is the utilization of new synthesis methods. Microemulsion and polyacrylamide gel methods are the two methods that were used for the synthesis of zinc aluminate nanoparticles for this study. The powders obtained from these two synthesis methods were characterized using the X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV–Vis) which were utilized as photocatalysts in the photocatalytic degradation reaction of methylene blue (MB). The results demonstrated that the nanoparticles synthesized in both methods were of single-phase zinc aluminate with a spinel structure. The crystallite size obtained for zinc aluminate synthesized using the microemulsion method was 21.7 nm, whereas, in the polyacrylamide gel method, it was 26.3 nm. Microscopic images represented smaller and more uniform particle sizes in the nanoparticles obtained by the microemulsion method. The band gap energy of zinc aluminate nanoparticles obtained using microemulsion and polyacrylamide gel methods was 4.15 and 3.82 eV, respectively. Similarly, the results of MB removal showed that zinc aluminate nanoparticles synthesized using the microemulsion method and polyacrylamide gel, respectively, were 100% and 71% after 120 min. In the second phase of this study, silver nanoparticles were added to zinc aluminate nanoparticles during the synthesis process. X-ray diffraction showed that silver nanoparticles are formed metallically next to zinc aluminate. Moreover, the addition of silver decreased the crystallite size and slightly increased the band gap energy of zinc aluminate. The results of MB dye degradation tests in the presence of ZnAl2O4–Ag nanocomposites showed that the kinetics of dye degradation increased when the silver increased up to 5 wt%. Finally, the mechanism studied on dye degradation using scavenger agents showed that the main agents of dye degradation are the superoxide radical and the holes created in the valence band. It was consistently confirmed by examining the valence and conduction band potentials and also by comparing these potentials with those responsible for producing superoxide and hydroxyl radicals.

A comprehensive evaluation of the photo-catalytic performance of recycled glass aggregate incorporated permeable cement-based mortar with TiO2 as a photo-catalyst

This study aims to investigate the effectiveness of incorporating recycled glass aggregate (RGA) in TiO2-containing cement-based permeable mortars in terms of their photo-catalytic performance. To do this, standard and permeable mortars were produced with the RGA utilization rates of 15% and 30% (by weight of total aggregate content). Photo-catalytic activity of the mortars was evaluated through the determination of NOx and NO degradation capacities, NO2 transformation ratio and the selectivity, and their photo-catalytic activity performances were compared with each other and with reference specimens without any RGA to assess the efficiency of RGA utilization in terms of photo-catalytic degradation. Microstructural and mechanical properties of the mortars were also evaluated by performing scanning electron microscope (SEM) analysis and compressive strength test, respectively. According to the experimental results, regardless of curing age, utilization of RGA as aggregate caused decrements in the strength results because of the lower adherence capability with matrix. NOx degradation results indicated that permeable structure of the photo-catalytic mortars allows NOx species to diffuse to the inner part of the hardened specimen in favor of stimulation of photo-catalytic degradation reactions in deep along with the surface. RGA utilization was also allowed to penetration of UV lights throughout the matrix providing improved the photo-catalytic activity for the TiO2-containing specimens. The correlation between the selectivity results and the degradation rates of NOx demonstrates the reliability of selectivity as a parameter for evaluating the photo-catalytic performance.

Promotion effect of Ga3+ in ZnAlGa-x mixed oxides obtained from their layered double hydroxides on the enhancement in the transient photocurrent response, the inhibition in the recombination rate of photogenerated (e−, h+) charges and the photocatalytic activity in the photodegradation of 4-chlorophenol

ZnAlGa-x (x = 0, 0.5, 0.8, 1.0, 2.0 and 3.0 mol % of Ga3+) mixed oxides (MOs) obtained by calcination of their corresponding layered double hydroxides (LDHs) were characterized and evaluated in the photodegradation of 4-chlorophenol in aqueous media (4-CP) using UV light irradiation. Structural studies by X-ray diffraction (XRD) of ZnAlGa-x MOs indicated that the incorporation of a small molar concentration of Ga3+ (0.5–0.8 mol %) within the ZnAl LDH structure changed the micro-crystalline structure to an amorphous structure. A small molar content of Ga3+ in the ZnAlGa3+ MOx promotes the formation of a high amount of structural oxygen vacancies as evidenced by Raman and EPR spectroscopy studies. Transient photocurrent response (TPC) and fluorescence spectroscopy experiments reveal that the incorporation of a small molar concentration of Ga3+ in the structure of ZnAl MO promotes the enhancement in the transient photocurrent response, the separation of photogenerated charges and the inhibition of the recombination rate of (e−, h+) pairs. Furthermore, ZnAlGa-x MOs with a small molar concentration of Ga3+ reduced their band gap energies below of 3.0 eV. ZnAl MO photodegradated 69.0 % of 4-CP after 4 h of reaction. However, the photoconversion % of 4-CP increased to 80–90 % at 3 h of reaction using ZnAlGa-x MOs with a small molar concentration of Ga3+. ZnAlGa-x with small Ga3+ concentration mineralized approximately 70–75 % of total disolved organic carbon at 3 h of reaction. The photocatalytic degradation reaction of 4-CP fitted well to a pseudo-first order kinetics of Langmuir-Hinshelwood-type. The kinetic parameters of ZnAlGa-x MOs confirmed that ZnAlGa-0.8 MO was the best photocatalyst to photodegradate 4-CP in aqueous media. The highest photocatalytic activity and efficacy of ZnAlGa-0.8 MO to mineralize 4-CP in aqueous medium may be due to its higher amount of oxygen vacancies contained in its structure promoting a better separation of charges and the inhibition of the recombination rate of photogenerated (e−, h+) charges.

Degradation of multiple xanthates using highly efficient visible light-responsive BiOBr-TiO2 composite photocatalysts

BiOBr-TiO2 (BT) composite photocatalysts were synthesized by using a two-step method including hydrothermal synthesis and water-bath precipitation. The microstructural characterization analysis proved that high-crystallinity and high-purity binary BT materials were achieved without by-products. TiO2 nanoparticles with a diameter of approximately 15 nm were decorated on multi-layered BiOBr nanosheets. The results showed that BT had highly-improved adsorption capacity and photocatalytic efficiency in comparison to pristine BiOBr and TiO2. The reaction rate constant of the optimal BT-2 composite photocatalysts for the degradation of 20 mg/L sodium ethyl-xanthate could reach 0.06496 min−1, which was 2.7 and 40.3 times than pure BiOBr and TiO2, respectively. The free radical scavenger test demonstrated that photogenerated holes were the main active species in the photocatalytic degradation reaction process. A possible degradation pathway for SEX molecules was provided through the interaction of visible light and BT-2 photocatalyst. The as-prepared BT materials can be used as efficient photocatalysts to completely degrade various types of xanthates under visible light.

CZTS (Cu2ZnSnS4)‐based Nanomaterials in Photocatalytic and Hydrogen Production Applications: A Recent Progress towards Sustainable Environment

AbstractA variety of unique compounds have been examined to accommodate the current demand for useful multi‐functional nanomaterials, copper‐based quaternary CZTS semiconductors are one of them. Due to their special characteristic features like non‐toxicity, cheap, and abundance, they have been recommended in recent literature for various applications. Apart from individual CZTS, different hetero‐structures have also been prepared with different compounds which is well discussed and elaborated in this article. Additionally, their preparation methods, properties, and application viability have also been discussed comprehensively. The application of CZTS such as photocatalytic dye degradation and hydrogen evolution reaction has been elaborated on in this article identifying their benefits and challenges to give readers a thorough visualization. Apart from that, challenges reported in studies, a few approaches are also mentioned to possibly counter them.

Solution combustion synthesis of metal tungstates for chromium reduction and dye degradation for environmental remediation

Metal tungstates CuWO4 and ZnWO4 nanoparticles were synthesized by simple, efficient, low temperature solution combustion synthesis using metal nitrate and ammonium tungstate. The prepared samples were characterized by different physicochemical characterization techniques i. e.XRD, FTIR, SEM, EDAX, UV–vis DRS, PL and XPS techniques. The petal and flower like morphology of these samples were obtained by using SEM analysis. Based on this novelty, we have studied the photodegradation of methylene blue and rhodamine B dyes in visible light. Results of photocatalytic dye degradation reaction reveal that both the tungstate’s can be employed as photocatalyst under visible light irradiation. ZnWO4 nanoparticles show comparatively higher activity than that of CuWO4, it may due to structural property as well as completely filled d10 orbital of Zn. Both CuWO4 as well as ZnWO4 were also applied to reduce toxic Cr(VI) into harmless Cr(III). This work implemented for the betterment of environmental remediation to the society.

Simple and fast synthesis of BiOBr/[Bi6O5(OH)3](NO3)5·3H2O composites for efficient photocatalytic degradation of RhB under visible light

In this study, a heterostructure photocatalyst consisting of Bi6O5(OH)3](NO3)5·3H2O (was denoted as BiOOHN) and BiOBr was fabricated via a simple and economic co-precipitation method. In this method, the amount of Br in the composition was controlled by changing the volume of hydrobromic acid (HBr) during the manufacturing process. The photocatalytic performance of the prepared samples by photodegradation of rhodamine B (RhB) solution under visible light radiation was investigated and the optimum amount of HBr was obtained. The results showed that BiOBr/BiOOHN composite has higher photocatalytic efficiency compared to pure BiOOHN and BiOBr, so that almost 100 % of RhB solution was degraded in the presence of BiOBr/BiOOHN composite photocatalyst during 100 min, while this value was equal to 0 % and 21 % for pure BiOOHN and BiOBr, respectively. Results indicated that the BiOOHN band gap is in the ultraviolet region (3.45 eV) and not possible to activate this sample to generate electron-hole pairs under visible radiation. While the energy gap of the samples synthesized in the presence of HBr was around 2.90 eV, which enables the activation of these compounds under visible radiation to generate electron-hole pairs for photocatalytic reactions. Therefore, the weak BiOOHN photocatalytic performance is attributed to the its wide band gap energy in comparison with other samples. Also, the better performance of composite samples compared to pure BiOBr is owing to the formation of a heterostructure between BiOOHN and BiOBr. It leads to better separation of electron-hole pairs at the interface of two semiconductors and hinders their recombination, which improves photocatalytic performance. Also, a mechanism for the photocatalytic reactions of RhB degradation was proposed based on experimental data and the experiment of trapping active species. According to this mechanism, the holes and free hydroxyl radicals (•OH) play a key role in the photocatalytic degradation reactions of RhB.

A novel bimetallic (Au-Pd)-decorated reduced graphene oxide nanocomposite enhanced Rhodamine B photocatalytic degradation under solar irradiation

Nowadays, water quality is one of the main challenges facing humanity. Recently, hybrid nanomaterials have attracted great attention because they can treat water solutions. In this study, Sol-Immobilization synthesized monometallic (Pd and Au) and bimetallic (Pd-Au) hybrid nanomaterials supported on reduced graphene oxide (rGO) were synthesized as catalysts for the photocatalytic Rhodamine B degradation under direct sunlight. The as-synthesized nanomaterials were characterized using XRD, Raman spectroscopy, UV-DRS spectrophotometer, HR-TEM techniques, and X-ray Photoelectron Spectroscopy. The catalytic activities of Pd/rGO and Au/rGO were compared with those of Aux-Pdy/rGO, and a higher photocatalytic degradation efficiency was found for the bimetallic-supported rGO sample. At optimum conditions, Au0.75-Pd0.25/rGO achieved the best dye degradation efficiency of 98%. The reusability study results showed that Au0.75-Pd0.25/rGO retained 89% of its initial activity after five successive uses. The scavenging study results proved that hydroxyl radicals are the major reactive species in the photocatalytic degradation reaction. These findings indicate that Au0.75-Pd0.25/rGO catalyst is a promising material for the treatment of water contaminated with organic dyes under sunlight.

Insight into tetracycline photocatalytic degradation mechanism in a wide pH range on BiOI/BiOBr: Coupling DFT/QSAR simulations with experiments

A single hydrothermal reaction was used to create BiOI/BiOBr composites, which demonstrated good sunlight-driven photocatalytic degradation activity of tetracycline (TC) over a broad pH range and the degradation efficiency can be stable at about 90%. Moreover,·O2- has been identified as the most important active ingredient in the photocatalytic system. Density functional theory (DFT) calculations were used to investigate the electron transfer mechanism of BiOX heterojunctions on a molecular scale, as well as to propose possible photocatalytic degradation mechanisms and reaction sites for tetracycline in different deprotonated forms at a wide range of pH values. The quantitative structure-activity relationship (QSAR) was also used to assess the toxicity of the intermediates. In summary, this study presents new concepts for investigating the photodegradation behavior of antibiotics throughout a wide pH range, which is predicted to be employed for surface water remediation.

Porous cyclopentadiene unit-incorporated graphitic carbon nitride nanosheets for efficient photocatalytic oxidation of recalcitrant organic micropollutants in wastewater

For the purpose of searching for efficient photocatalysts to deal with recalcitrant organic micropollutants in wastewater, here an in-situ supramolecule self-assembly-thermal polymerization strategy is developed to prepare a series of porous cyclopentadiene (CPD) unit-incorporated g-C3N4 ultrathin nanosheets (CCPD-g-C3N4). The CCPD-g-C3N4 demonstrate CPD unit doping level-dependent and remarkably enhanced visible-light photocatalytic oxidation efficiency towards two organic micropollutants, acetaminophen and methylparaben, in which the optimized CCPD-g-C3N4-2 shows 6.1 and 3.5 times higher acetaminophen and methylparaben degradation rate than bulk g-C3N4; moreover, CCPD-g-C3N4-2 is still robust and efficient in the treatment of five mixed organic micropollutants in pharmaceutical wastewater, and the satisfactory micropollutant removal efficiency is obtained in a wide pH window and the presence of high concentrations of inorganic anions and cations as well as dissolved organic matters. Theoretical calculation combined with experimental test reveal that CCPD-g-C3N4 can significantly reduce ecological risk of the target pollutant after the photocatalytic degradation reaction. Such enhanced photocatalytic oxidation efficiency is dominated by the accelerated charge carrier separation dynamics and extended visible-light response region due to the incorporation of CPD units, which finally lead to the generation of abundant reactive oxygen species to degrade and mineralize target micropollutants efficiently.

Synthesis of Tungsten-Modified Sn3O4 through the Cetyltrimethylammonium Bromide-Assisted Solvothermal Method for Dye Decolorization under Visible Light Irradiation

Novel tungsten-modified mixed-valence tin oxides (Sn3O4) with two oxidation numbers, such as Sn2+ and Sn4+, were successfully prepared by the cetyltrimethylammonium bromide (CTAB)-assisted solvothermal method in one-step using tin (II) chloride dihydrate and sodium tungstate (IV) dihydrate as the precursors for dye degradation of methyl orange (MO) under visible light irradiation. The synthesized materials were characterized by various techniques to investigate the surface/structural morphology and the optical property. The presence of tungsten and the optimized amount of CTAB in the preparation method were favorable for the photocatalytic dye degradation reaction. In particular, when 0.03 of CTAB was added to W-modified Sn3O4 (W-Sn3O4@CTAB) and its concentration was 0.6 mg/mL, 10 mg/L of MO could be decolorized almost completely in 40 min, with the apparent reaction rate constant of 0.0496 min−1. The improvement of photocatalytic activity for this proposed W-Sn3O4 results from increased reduction power, enhanced separation of electron–hole pairs, extended visible light absorption range, and optimized band structure by CTAB additive. The radical trapping experiments showed that the main reactive species during the photocatalytic reaction are superoxide ions. The developed photocatalysts may contribute to the development of environmental improvement technology.

Deployment of the one-step solvothermal method to synthesize high-performance ZnO nanorods in photocatalytic NO degradation: A novel investigation

Nowadays, photocatalysis has attracted much attention due to its ability to degrade NO at low concentrations, combined with a cheap, sustainable, and environmentally friendly process. Recent studies highlights zinc oxide nanorods (ZnO NRs) may be applied as potential photocatalysts due to their efficient charge transport, and high performance. In this study, a high surface area of ZnO NRs was achieved via a one-step solvothermal method with control of reaction time and temperature. Additionally, the synthesized ZnO NRs was deployed to comprehensively evaluate the photocatalytic activity of NO degradation. The results indicated that the synthesized ZnO NRs at 100 °C for 6 hours exhibited the most favorable performance in term of photocatalytic NO degradation (78.8% under solar light and 62.2 % under visible light), along with low toxicity (DeNOx index of 268.4). The improved photocatalytic efficiency of these samples can be attributed to their high aspect ratio and the presence of oxygen defects, which effectively capture and impede the recombination of photogenerated electrons. Furthermore, the ZnO NRs possess high stability under visible light irradiation, experiencing only an 8.7 % reduction after five reuses. Finally, trapping experiments and ESR analysis were used to explore the mechanism of the photocatalytic NO degradation reaction.

Influence of Different Capping Agents on the Structural, Optical, and Photocatalytic Degradation Efficiency of Magnetite (Fe3O4) Nanoparticles.

Octylamine (OTA), 1-dodecanethiol (DDT), and tri-n-octylphosphine (TOP) capped magnetite nanoparticles were prepared by co-precipitation method. Powder X-ray diffraction patterns confirmed inverse spinel crystalline phases for the as-prepared iron oxide nanoparticles. Transmission electron microscopic micrographs showed iron oxide nanoparticles with mean particle sizes of 2.1 nm for Fe3O4-OTA, 5.0 nm for Fe3O4-DDT, and 4.4 nm for Fe3O4-TOP. The energy bandgap of the iron oxide nanoparticles ranges from 2.25 eV to 2.76 eV. The iron oxide nanoparticles were used as photocatalysts for the degradation of methylene blue with an efficiency of 55.5%, 58.3%, and 66.7% for Fe3O4-OTA, Fe3O4-DDT, and Fe3O4-TOP, respectively, while for methyl orange the degradation efficiencies were 63.8%, 47.7%, and 74.1%, respectively. The results showed that tri-n-octylphosphine capped iron oxide nanoparticles are the most efficient iron oxide nano-photocatalysts for the degradation of both dyes. Scavenger studies show that electrons (e-) and hydroxy radicals (•OH) contribute significantly to the photocatalytic degradation reaction of both methylene blue and methyl orange using Fe3O4-TOP nanoparticles. The influence of the dye solution's pH on the photocatalytic reaction reveals that a pH of 10 is the optimum for methylene blue degradation, whereas a pH of 2 is best for methyl orange photocatalytic degradation using the as-prepared iron oxide nano-photocatalyst. Recyclability studies revealed that the iron oxide photocatalysts can be recycled three times without losing their photocatalytic activity.

Activation of 2D cobalt hydroxide with 0D cobalt oxide decoration for microplastics degradation and hydrogen evolution

The 2D semiconductors are important players in environmental and energy fields due to their unique catalytic and physical properties defined by their dimensionality. Versatile functionalities on one 2D matrix will enlarge its application scopes but require dedicated engineering paths. In this work, we present a cross-dimensional strategy by decorating 0D Co3O4 onto 2D Co(OH)2 to form a multifunctional photocatalyst. The one-pot hydrothermally synthesized Co3O4@Co(OH)2 composite is capable of degrading polystyrene microplastics with an efficiency of 40% under 0.495 W white LED illumination. In a separated experiment, H2 evolution reaction from water splitting was evaluated in absence of sacrificial agents leading to 43 μmol g−1 and to an apparent quantum efficiency of 3.48% at 420 nm. The study of the energy band diagrams by UV–Visible and ambient photoemission spectroscopy and the analysis of the radicals involved in the reaction of photocatalytic degradation allow to unveil the mechanisms for both the processes herein studied. Finally, we could confirm that the heterostructure benefits the redox potentials of 2D and 0D counterparts and facile electron transfers when crossing two different dimensions. These results provide guidelines and inspiration for cross-dimensional activations of low-dimensional materials for versatile functionalities.

Optimization of photocatalytic degradation of malachite green using nano-scaled V/CeO2-functionalized steel-slag-based catalyst by response surface design approach

The utilization of steel slag with high added value is an important means for sustainable development of the iron and steel industry and environment. A new nano-scaled V/CeO2-functionalized steel-slag-based catalyst (V/CeO2-SC) was prepared. The XPS results revealed that V was embedded in the CeO2 lattice with V4+ and V5+ forms. The regression equation analysis of variance told that the order of influencing factors on malachite green dye degradation rate is: catalyst dosage > V doping amount > malachite green dye concentration. The optimum values of the parameters were dye concentration 10 mg/L, catalyst dosage 0.1 g, and V doping amount 1wt%. Under the optimal condition, the predicted and actual response values of the degradation rate of malachite green dye were 100.00%. UV–Visible light absorption spectroscopy results demonstrated that after the photocatalytic degradation reaction, the absorption peak of the malachite green dye solution almost completely disappeared, indicating that the malachite green dye solution was almost completely degraded. The excellent degradation activity of the 1V/CeO2-SC specimen was attributed to the co-action of the high SBET, large mesoporous volume, and the coupled semiconductors formed by V-doped CeO2 and FeO in the catalyst carrier. A possible photocatalytic degradation mechanism of the V/CeO2-SC specimen was proposed.

Effective removal of azithromycin by novel g-C3N4/CdS/CuFe2O4 nanocomposite under visible light irradiation

In this study, the visible light active pristine, binary and ternary g-C3N4/CdS/CuFe2O4 nanocomposite is prepared through a coprecipitation-assisted hydrothermal technique. The characterization of the as-synthesized catalysts was conducted using various analytical techniques. When compared with pristine and binary nanocomposites, the ternary g-C3N4/CdS/CuFe2O4 nanocomposite exhibits higher photocatalytic degradation of azithromycin (AZ) under a visible light source. Ternary nanocomposite exhibits high AZ removal efficiency of about 85% within 90 min of the photocatalytic degradation experiment. Enhanced the visible light absorption ability and the suppression of photoexcited charge carriers is also achieved by forming heterojunctions between pristine materials. The ternary nanocomposite exhibited ∼2 times higher degradation efficiency than CdS/CuFe2O4 nanoparticles and ∼3 times higher degradation efficiency than CuFe2O4. The trapping experiments were conducted and it shows superoxide radicals (O2•-) are the predominant reactive species involved in the photocatalytic degradation reaction. This study provided a promising approach for the treatment of contaminated water using g-C3N4/CdS/CuFe2O4 as a photocatalyst.